Known Issues

This page summarizes known issues with IPAM Grid Manager that may be relevant to campus network administrators.

Authentication

  • Even though they both ultimately derive from the same Active Directory user object, Grid Manager regards `yournetid` (the SAML identity that you use for SSO Login) and `yournetid@illinois.edu` (the userPrincipalName identity that you use for API access and the optional Alternative Login Method) as two separate users who happen to have the same permissions.
    This has the following practical consequences:

    • Each user profile has its own independent set of GUI personalizations, so e.g. Smart Folders or table customizations you create for your SSO Login identity will not be visible when you log in with your userPrincipalName identity (nor vice versa).  This can be a confusing user experience, especially if you frequently switch back and forth, so our general recommendation for most people is to always access the GUI using “SSO Login”.

    • User profile settings, Smart Folders, Scheduled Tasks, etc that belong to your SSO Login identity cannot be managed using the API.
    • Here is a partial (not exhaustive) list of user profile customizations you may wish to consider manually recreating when you switch login methods:
      • (your username in upper-right corner) > Profile: Table Size
      • Finder > Smart Folders
      • Finder > Bookmarks
      • column customizations for various tables (e.g. adding “Network Name” to both Data Management > IPAM and Data Management > DHCP > Networks > Networks)
      • saved Quick Filters for various tables
      • “Toggle Advanced Mode” in various dialog boxes
      • “Toggle flat view” in Data Management > DNS > Zones > Records
      • “Include Extensible Attributes Values” in Search > Advanced

Discovered Data

  • Please avoid using the “Ping” (and “Multi-Ping”) toolbar buttons within IPAM.  Successful pings have the side effect of storing “Discovered Data” for the IP which unfortunately cannot be cleared using normal permissions; it must be cleared by hostmgr (or a nightly automated script) on your behalf.  This Discovered Data can inconvenience you in several ways, including manifesting visually in IPAM as a purported “conflict” or “unmanaged” address, and/or preventing you from creating a Range.

Leases

  • In IPAM view (Viewing Leases in a Network), “Static” Leases from Fixed Addresses or DHCP-enabled Hosts are only displayed if the IP in question happens to fall within a DHCP Range.
  • Depending on your individual network permissions, some users may experience a significant delay and eventual timeout when clicking on the Current Leases tab.  The text of the error message is:
    “The system is taking longer than expected to complete your request. The system will continue to process any changes you made in the background. Please wait, then check whether your changes were applied. If you did a search, please refine your query and retry your request.”
    Workarounds:
    • wait for it to time out, then apply a Filter (e.g. “IP Address” “begins with” …) to limit the scope of the query
    • use one of the other two methods described in Managing DHCP Leases instead
  • Grid Manager does not appropriately account for Abandoned Leases when calculating the DHCP utilization statistics (per Range and per Network) which are shown in Grid Manager, returned by the API, tracked by dhcpmon, and used to trigger DHCP Threshold Email Alerts.  For example, a Range which contains 90% Active Leases and 10% Abandoned Leases will not generate an alert because Grid Manager considers it to be only 90% utilized, even though live clients may be unable to obtain a lease (depending on how many of the Abandoned Leases are actually still in use on the network).
    Workarounds:
    • dhcpmon has been enhanced to display the most recent Abandoned lease count per network (data updated once per day)
    • hostmgr now receives automated notifications regarding networks which are over 95% full including Abandoned leases, so we can manually reach out to CDB network contacts to let them know when this problem has become serious
  • Addresses within Reserved Ranges are counted (along with DHCP Ranges) in the per-Network DHCP Utilization statistics shown in Grid Manager, returned by the API, and tracked by dhcpmon.  Consequently, the presence of Reserved Ranges may cause a network to appear less full than it actually is.  This does not affect Email Alerts (which apply individually to each Range).
    • Workaround: Edit the Reserved Range and check “Disable for DHCP”.

Search

  • Basic Search for DNS Name does not currently find Host Aliases.
  • Advanced Search for an IPv6 address will only succeed if you enter the exact string representation of the address that Grid Manager uses internally.  For example, you will not find “2620:0:e00:b::53” by searching for “2620:0000:0e00:000b::53” (extra leading zeros) or “2620:0:e00:b:0:0:0:53” (no double colon abbreviation), even though these are all valid representations of the same IPv6 address.
    • Workaround: use Basic Search by IP Address instead.

DNS Traffic Control

  • DNS Traffic Control may return your fallback records (instead of synthesized responses) for about 1 second after a restart of services in which other DTC configuration changes are being applied, even if those changes have nothing to do with your LBDN.  Mitigation: choose good fallback records.
  • Grid Manager currently displays fallback records in normal font instead of strikethrough font

Misc

  • Due to shared implementation logic under the hood, if you try to create a Fixed Address with MAC address “00:00:00:00:00:00”, IPAM will silently create a “Reservation” object instead.  This is especially confusing because there is no way to convert a “Reservation” back into a Fixed Address later; it must be deleted.
    • Workaround: if you need a dummy placeholder MAC address, consider using one that begins with “02:”